This interdisciplinary research program, in progress since 1958, encompasses three projects which share a common framework in studying sociopsychological change in adult life. Its objective is to differentiate extrinsic and intrinsic factors in life course change in mental and physical functioning and to trace consistencies and inconsistencies in perceptual and coping processes that prove adaptive at successive life stages. A multidimensional concept of mental health is used and emphasis is given to subjective perception of circumstantial reality. The longitudinal study of transitions examines the interrelationships of (1) situational factors, (2) perceptual characteristics, (3) values, goals, and goal-motivated behavior, and (4) indicators of adaptation. Divorce: A psychosocial study of adaptation will examine internal and external factors in coping and adaptation to divorce among recently divorced middle-aged individuals. Leisure as a psychological resource will investigate the interrelationships of work and leisure, the satisfactions gained from each, and their contribution to successful adaptation over the life course. BIBLIOGRAPHIC REFERENCE: Lowenthal, Marjorie Fiske and Betsy Robinson, "Social Networks and Isolation," invited chapter, Robert H. Binstock and Ethel Shanas (Eds.), The Handbook of Aging and the Social Sciences, New York: Van Nostrand Reinhold, (1976).